[Duadic codes][1]} [2]}
Let \(\lbrace S_1,S_2\rbrace \)  be a splitting of \(\mathbb {Z}_n\)  over \(\mathbb {F}_q\) .
Then the linear cyclic codes with the defining sets \(S_1 \cup \lbrace 0\rbrace \)  and \(S_2 \cup \lbrace 0\rbrace \)  are called a pair of even-like duadic codes. The linear cyclic codes with the defining sets \(S_1\)  and \(S_2\)  are called a pair of odd-like duadic codes.
